Pheromone signals are known to play a major role in mammalian reproduction and behavior. In the case of pigs, females will signal when they are coming into oestrus and using pheromones and distinctive behavior (e.g., lordosis or standing reflex), they will solicit approaches by the male.
Early scientific literature pointed to salivary steroid molecules androstenone and androstenol as the recognized boar pheromone that is responsible for inducing reproduction in the female pig (see Melrose et al., Androgen steroids associated with boar odour as an aid to the detection of oestrus in pig artificial insemination, The British Veterinary Journal, 127, 497-502 (1971); see also Perry et al., Pig courtship behaviour: pheromonal property of androstene steroids in male submaxillary secretion, Animal Production, 31, 191-199 (1980)). Products such as Boarmate™ (ITSI, Canada), which contain Androstenone, have long been sold on the market to detect female pigs in heat and have been used to save time and money when breeding pigs.
However, the synthetic products presently on the market are not always successful in replicating boar saliva to induce sow reproductive behavior and performance. As a result, determining when female pigs are in heat becomes increasingly labor intensive, costly, and inefficient, as more boars may be needed to be kept on site, females in heat may be difficult to find, and reproductive successes may be decreased.
Accordingly, there is a need within the industry for a synthetic boar saliva composition that has a greater likelihood of inducing reproductive behavior and increasing reproductive success and productivity in female pigs.